Polypropylene fibers of improved dyeability containing a terpolymer of a vinylpyridine and alkyl acrylates or methacrylates

ABSTRACT

A DYEABLE POLYPROPLENE FIBER COMRPISING POLYPROPYLENE IN ADMIXTURE WITH A COPOLYMER COMPOSED MAINLY OF VINYLPRIDINES AND ALKYL ACRYLATES OR ALKYL METHACRYLATES HAVING AN ALKYL GROUP CONTAINING 16 TO 20 CARBON ATOMS, AND A PROCESS FOR DYEING SAID FIBER CHARACTERIZED IN THAT THE FIBER IS TREATED WITH PHOSPHITE ESTER OR ALKYLPHENOLS TO MAKE THE FIBER EXCELLENT IN FASTNESS TO LIGHT.

United States Patent Office 3,639,513 Patented Feb. 1, 1972 US. Cl. 260-878 R 5 Claims ABSTRACT OF THE DISCLDSURE A dyeable polypropylene fiber comprising polypropylene in admixture with a copolymer composed mainly of vinylpyridines and alkyl acrylates or alkyl methacry lates having an alkyl group containing 16 to 20 carbon atoms, and a process for dyeing said fiber, characterized in that the fiber is treated with phosphite esters or alkylphenols to make the fiber excellent in fastness to light.

This invention relates to polypropylene fibers having improved properties, particularly excellent dyeability and adaptability as textile fibers, and a process for dyeing such fibers.

As is well known, crystalline polypropylene has excellent physical and chemical properties and is useful as material for preparing fibers and films. On the other hand, however, it suffers from such drawbacks that, due to, however, crystalline polypropylene is low in afiinity for dyes and is ditiicultly dyeable, and thus the utility thereof has been restricted.

In order to overcome the above drawbacks, there have heretofore been proposed various processes. For example, as a process for coloring polypropylene, there has been adopted a dope dyeing with pigment. This method, however, is greatly restricted in variety and, brightness in colors of the resulting colored fibers. Further, as processes for improving the dyeability of polypropylene, there have been proposed many methods. For example polypropylene is admixed with a dyeable polymer, e. g. polyamides, polyesters, or vinylpyridine polymers, or with metal-containing organic compounds. However, because of the incompatibility of these agents with polypropylene fibers obtained according to the above methods suffer from such drawbacks that the fibers are broken during the Spinning and stretching process; that the fibers cannot be dyed to deep shade; that the incorporated dyeability-improving these agents dissolving out during dyeing and scouring steps to make it impossible to obtain dyed fibers bright in color as well as to redye the fibers.

In order to overcome the above drawbacks, US. Pat. 3,156,743 has proposed a method in which a polymer of alkyl acrylates or methacrylates having an alkyl group containing 1 to 12 carbon atoms or a copolymer of said acrylates with vinylpyridines or acrylamides mixed with polypropylene and spun to obtain a dyeable fiber. The fiber obtained according to the above method has considerably favorable dyeability for disperse dyes, but in dyeing with acid dyes, the added polymer dissolves out into the dye bath, with the result that not only the fiber is lowered in dyeability but the dyed fiber is poor in color depth and brightness.

In an attempt to overcome such drawbacks, the present inventors made various studies to find that the polymer to be mixed with polypropylene should have such properties as mentioned below.

That is, the polymer should be one which has a proper hydrophilic and hydrophobic property, shows excellent afiinity for acid dyes, has proper compatibility with polypropylene, and does not deteriorate the excellent properties inherent to polypropylenev Further, the polymer should be one which, in a fiber obtained by spinning and stretching a mixture of polypropylene and the polymer, can take such a form which is macroscopically homogeneously dispersed in the polypropylene while, microscopically, it has distributed in a heterogeneous state. That is, the incorporated polymer itself should form a continuous micro-fibril structure in the polypropylene. In addition, when viewed from the standpoint of mechanical properties and texturizability of the polymer should be one having such a structure as to provide an interaction sumcient to transmit a stress externally applied to the fiber.

As the result, the inventors discovered the following facts:

In case a polymer of the conventionally known alkyl acrylates or methacrylates having an alkyl group containing 1 to 12 carbon atoms, or a copolymer of Said acrylates and vinylpyridines or acrylamides are used as a dyeabilityimproving agent for polypropylene, the polymer and the polypropylene tend to separate from each other during heating and melting due to insufficient compatibility between the two, and, in the extruded filament, the polymer and the polypropylene liable to be peeled each other owing to drafting or stretching during spinning in fiber forming. Consequently, in the resulting fiber, the polymer is in an unhomogeneously dispersed state and does not form continuous microfibril, so that the fiber is lowered in dyeability due to dissolving-out of the dyesite into the dye bath; the dyed fiber is lowered in color-depth and brightness; a texturized fiber obtained therefrom is deteriorated in crimpability and crimp stability, and a knit or woven product thereof is also deteriorated in such fiber property as dimensional stability and the like. In contrast thereto, when the copolymer employed in the present invention, which is composed mainly of a vinylpyridine and alkyl acrylates or methacrylates having alkyl group containing 16 to 20 carbon atoms, is used as a dyeability-improving agent for polypropylene, the compatibility of the copolymer with the polypropylene is greatly improved and therefore, in the resulting fiber, the copolymer is homogenous dispersed macroscopically, and is heterogeneously dispersed microscopically, and forms a continuous micro-fibril structure. Further, in dyeing the fiber with acid dyes, the copolymer swells in an aqueous dilute sulfuric acid solution employed as the dye bath but does not dissolve even at the boiling point of the solution, with the result that not only the fi ber can be dyed into a deep shade, but also the dyed fiber is excellent in color-depth and brightness. Furthermore, the fiber shows excellent mechanical properties and texturizability, by virtue of such a favorable fiber structure as mentioned above, and the crimpability and crimp stability of texturized fiber and the dimensional stability of knit or woven product thereof are markedly excellent, as well.

It has further been found that when the copolymer comprizing an alkyl methacrylate having an alkyl group containing 16 to 20 carbon atoms is used, a part of the copolymer added to polypropylene causes local degradation during spinning, and the use of said copolymer is somewhat inferior in fiber properties to the case where the alkyl acrylate copolymer is used. In order to effectively achieve the present invention, the use of the alkyl acrylate copolymer is preferable.

Based on the detailed knowledge as mentioned above, the present inventors made earnest studies to accomplish the present invention, the gist of which resides in that polypropylene is mixed with a copolymer composed mainly of a vinylpyridines and alkyl acrylates or methacrylates having an alkyl group containing 16 to 20 carbon atoms.

The first object of the present invention is to provide a polypropylene fiber excellent in dyeability and in dye fastness properties, particularly fastness to light.

The second object is to improve the texturizability of said polypropylene fiber.

The third object is to provide a process for dyeing the dyeable fiber of the present invention, characterized in that the fiber is treated, either before, during or after dyeing, with a solution or emulsified dispersion containing at least one member selected from the group consisting of specific phosphite esters and alkylphenols, thereby the fastness to light of the dyed fiber is greatly improved.

In accordance with the present invention, there are provided a deyable polypropylene fiber and a process for dyeing said fiber, characterized in that polypropylene is mixed with 130% by weight based on the total polypropylene composition of a copolymer composed mainly of vinylpyridines and alkyl acrylates or methacrylates having an alkyl group containing 16 to 20 carbon atoms, and the mixture is subjected to shaping or the mixture is further incorporated with at least one member selected from the group consisting of nonionic surface active agents and/or polyethers, or at least one of specified phosphite esters, and then the mixture is subjected to shaping.

In practicing the present invention, the copolymerization of vinylpyridines with alkyl acrylates or methacrylates having alkyl group containing 16 to 20 carbon atoms may be effected according to any of the conventionally known suspension polymerization, emulsion polymerization, and bulk polymerization. The polymerization is desirably effected in the presence of a polypropylene powder.

Copolymer suitable for the objects of the present invention is one comprising 85-30% by weight of vinylpyridines and -70% by weight of an alkyl acrylates or methacrylates having alkyl group containing 16 to 20 carbon atoms and having a reduced viscosity (1 C:O.5 g./ 100 ml., same shall apply hereinafter) of 2.0 or less as measured at C. in a 9:1 benzene-alcohol mixed solution. However, the preferable range of the reduced viscosity of the copolymer varies depending on the molecular weight of the polypropylene to be mixed with said copolymer, and in case a high molecular weight polypropylene has been employed, a copolymer having a reduced viscosity more than 2.0 is sufficiently applicable, as well.

In case the copolymer contains more than 85% by weight of vinylpyridines, the copolymer is lowered in compatibility with polypropylene and is present in a fine granular form in the resulting fiber to make impossible the formation of micro-fibrils. Consequently, in dyeing the fiber with acid dyes, the copolymer is dissolved out into the dye bath, whereby not only the dyed fiber is deteriorated in color depth and brightness but also no fiber excellent in mechanical properties and texturizability can be obtained.

The amount of the coploymer in the present invention is most preferably 1-30% by weight based on the total polypropylene composition. In case the amount of the copolymer is less than 1%, no sutficient dyeability-improving effect can be attained, while in case the amount is more than 30%, the resulting fiber is undesirably deteriorated in efliciencies particularly fiber property and texturizability.

The objects of the present invention can be more effectively achieved by use of a ternary copolymer obtained by copolymerizing ethyl or methyl acrylate. That is, by copolymerization of a small amount of ethyl or methyl acrylate, the copolymer employed in the present invention is made easier in the formation of micro-fibrils having influence on the physical properties of the resulting polypropylene fiber. Therefore, when said ternary copolymer is used in the production of a crimped yarn, erg. a woolly texturized yarn or a textured yarn obtained by conjugate spinning, the crimped yarn is favorable in crimpability and crimp stability for the reasons mentioned above. Particularly in the production of a crimped yarn according to conjugated spinning, the use of other c0- polymer than that of the present invention results, due to insutficient compatibility with polypropylene, in such disadvantages that the copolymer does not uniformly disperse in the resulting fiber nor forms micro-fibrils. Consequently, the crimped fiber obtained sufiers from such drawbacks that the dyesite falls oif during dyeing to lower the dyeability of the fiber and the color depth and brightness of the dyed fiber. Moreover, due to insufficient compatibility of the copolymer with polypropylene, the fiber is markedly deteriorated in fiber efiiciencies such as crimpability and crimp retention or stabilty.

The most preferable composition ratio of the ternary copolymer obtained by further copolymerizing a small amount of methyl or ethyl acrylate is, based on 100% of the total composition, is 10-60% by weight of alkyl acrylates or methacrylates having alkyl group containing 16 to 20 carbon atoms, -30% by weight of vinylpyridines and 40% and/or less by weight of methyl or ethyl acrylate.

Typical examples of the alkyl acrylates or methacrylates having alkyl group containing 16 to 20 carbon atoms, which is a starting material for the preparation of the copolymer employed in the present invention, are cetyl acrylate, stearyl acrylate, eicosyl acrylate, cetyl methacrylate, stearyl methacrylate and eicosyl methacrylate. The typical examples of the vinylpyridine to be used are 2-vinylpyridine, 3-viny1pyridine, 4-vinylpyridine, 2-methyl- 5-vinylpyridine and 2-ethyl-5-vinylpyridine. In addition thereto, polymerizable vinylpyridines and vinylquinoline may also be used.

Further, in mixing polypropylene with the copolymer of the present invention, at least one member selected from the group consisting of nonionic surface active agents and/ or polyethers which are specified in the present invention is used, whereby the effects of the present invention can be further enhanced. That is, the use of the copolymer of the present invention in combination with at least one member selected from the group consisting of the specified nonionic surface active agents and/or polyethers has effective actions on the improvement in dispersibility of the copolymer in polypropylene, on the improvement in micro-fibrils formate of the copolymer in the resulting fiber and on the improvement in uniformity and fiber efficiencies of the fiber, and shows marked efiects to aid the diifusion of a dye into the fiber to improve the 'dyeability of the fiber and to improve the color depth and brightness of the dyed fiber.

The mixing of the present copolymer with the specified nonionic surface active agents and/or polyethers may be effected according to any of such procedures that the copolymer and the nonionic surface active agents and/or polyethers are mixed with polypropylene, or the nonionic surface active agents and/or polyethers are dispersed in a polymerization medium solution for the preparation of the present copolymer, the copolymer is taken out while incorporating the nonionic surface active agent and/or polyether into the copolymer, and then the copolymer is added to polypropylene. The amount of the above additives to be mixed is desirably 0.1-5 by weight based on the total polypropylene composition.

Typical examples of the specified nonionic surface active agent and polyether are polyethylene-oxide, polypropylene-oxide, polyisobutylene oxide, polytetrahydrofuran (polybutylene oxide), polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkyl amides, poloxyethylene alkyl amines, sorbitan derivatives, polyoxyethylene aryl ethers, polyoxyethylene aryl esters and polyoxyethylene-polyoxypropylene block copolymers. In practicing the present invention, at least one of the organo-phosphorus compounds specified in the present invention is used in combination, whereby the light fastness and the brightness of the resulting fiber, when dyed particularly to a light shade, can be greatly improved by the interaction of the copolymer employed in the present invention and the phosphite esters.

The phosphite esters specified in the present invention are compounds represented by the general formulae Ri-X R2XP R3X (I) wherein R R and R are, individually hydrogen atom, alkyl, aryl or aralkyl group; and X is oxygen or sulfur atom,

O CH: R4OP\ /C\ CH2 C1120 (11) wherein R and R are, individually, an alkyl, aryl or aralkyl group, and

wherein R R R and R are, individually, an alkyl, aryl or aralkyl group; and R and R are, individually, hydrogen atom or an alkyl group.

Concrete examples of such compounds are as follows:

These may be used either independently or in admixture of 2 or more, and the amount of such compound to be added is within the range of 05-20%, preferably ll0%, by weight based on the total polypropylene composition.

In dyeing the improved, dyeable polypropylene fiber of the present invention, it is not necessary to particularly limit scouring, dyeing and soaping processes, and acid dyes, acid mordant dyes, premetallized dyes and dlsperse dyes can be used.

Inherently, the improved polypropylene fibers of the present invention has excellent dyeability. However, in order to further improve the fastness to light of the fiber when dyed to a light shade, it is desirable to treat the fiber, either before, during or after the dyeing, with a solution or emulsified dispersion of a phosphite esters represented by any of said general Formulae I, II and III or of an alkylphenol represented by the general formula R av) The above phosphite esters or alkylphenols may be used either independently or in admixture of 2 or more.

In general, the fastness to light of a dyed fiber is dominated by the shade of the dyed fiber. In the case of a deep shade and the fastness to light is generally excellent, but in case of a light shade the fastness to light is generally poor. In accordance with the dyeing process of the present invention, the above drawback can be easily improved to a great extent.

Concretely, the dyeable fiber of the present invention may be treated with the above-mentioned phosphite esters or alkylphenols according to any of the following procedures: That is, the fiber may be treated, before dyeing, with a solution or emulsified dispersion of said compound;

- the above compound is added to a dye bath and the fiber is treated with said compound in the dye bath simultaneously with dyeing of the fiber; or the fiber is treated, after dyeing, with a solution of emulsified dispersion of said compound. The above compounds are used at a concentration of 0.1 to 50% by weight (OWF) based on the weight of the fiber.

If the preferable dyes usable in the present invention;

Acid dyes include:

Suminol Milling Red RS (C.I. Acid Red 99),

Solar Scarlet R (C.I. Acid Red 77),

Fenazo Scarlet B (Cl. Acid Red 66),

Kayaku Acid Fast Yellow G.G. (Cl. Acid Yellow 17),

Xylene Light Yellow 2GP (Cl. Acid Yellow 29),

Solway Blue BNl50 (Cl. Acid Blue 45),

Xylene Fast Blue P (Cl. Acid Blue 82),

Brilliant Alizaline Milling Blue G (Cl. Acid Blue 127),

and

Solway Green G-l50 (Cl. Acid Green 25).

Acid mordant dyes include:

Eriochrome Flavine R (CI. Mordant Yellow 26), Eriochrome Red B (C.I. Mordant Red 7),

Mitsui Alizaline Red S (Cl. Mordant Red 3), Solochromate Fast Blue B (Cl. Mordant Blue 7), and Solochrome Flavine G (C.I. Mordant Yellow 5).

Premetalized dyes include:

Carbolan Yellow 4G-150 (C1. Acid Yellow Cibalan Yellow GRL (C.I. Acid Yellow 116), Cibalan Blue BRL (Cl. Acid Blue Cibalan Scarlet GL (C.I. Acid Red 209),

Lanasyn Red BL (C.I. Acid Red 215),

Lanasyn Yellow 3GL (Cl. Acid Yellow 111), Lanasyn Brilliant Blue GL (C.I. Acid Blue 127), Neolan Yellow GR (Cl. Acid Yellow 99),

Neolan Red GRE (C.I. Acid Red 183), and

Neolan Blue 2G (C.I. Acid Blue 158).

Disperse dyes include:

Diacelliton Fast Yellow GF (C.I. Disperse Yellow 3), Diacelliton Fast Red RF (C.I. Disperse Red 17),

7 Diacelliton Fast Blue BF (Cl. Disperse Blue 14), Kayalon Fast Orange GR (C.I. Disperse Orange 3), Kayalon Fast Scarlet B (C.I. Disperse Red 1), Kayalon Fast Blue FG (C.I. Disperse Blue 6), Celliton Fast Blue Extra (C.I. Disperse Blue 1), Celliton Fast Yellow RR (Cl. Disperse Yellow 1), and Celliton Fast Scarlet R (C.I. Disperse Red 7).

In addition to the aforesaid additives, there may be incorporated, if necessary, antioxidant such as tetrakis [3- (4-hydroxy 3,5 di-tert-butylphenol) propionyl-oxymethyl]-methane, 1,3,5-tris (4-hydroxy-3,5-di-tert-butylbenzyl) 2,4,6 trimethylbenzene, and 4,4-thiobis (5- methyl-2-tert-butylphenol); peroxide decomposer such as dilauryl-thiodipropionate; ultraviolet [ray absorber such as 2-hydroxy 4 octoxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone and 2-[2 hydroxy-5-(l,l,3,3-tetramethylbutyl)-phenyl]-5-chlorobenzotriazole; higher fatty acid metal salts such as calcium stearate and zinc stearate; organo-tin compounds as viscosity controlling agents; titanium oxide; fluorescence whitening agents; antistatic agents; and low molecular weight polyethylene.

EXAMPLE 1 5 parts of a copolymer :05) comprising 30 parts of stearyl acrylate and 70 parts of Z-methyl-S-vinyl pyri dine was mixed with 95 parts of a crystalline polypropylene powder having an intrinsic viscosity (measured in tetraline at 135 C.; same shall apply hereinafter) of 1.4 and as an antioxidant 0.2 part of 4,4-thiobis (5-methyl-2- tert.-butylphenl). The mixture was shaped into pellets at 220 C., was subjected to melt-spinning at 270 C., and was stretched to times at 130 C. to obtain the dyeable fiber of the present invention.

For comparison, 5 parts of a copolymer comprising 70 parts of Z-methyl-S-vinylpyridine and 30 parts of ethyl acrylate was mixed with 95 parts of a crystalline polypropylene powder having an intrinsic viscosity of 1.4, and the mixture was treated in the same manner as above to obtain a fiber.

Thus obtained two fibers were examined in dyeability under the conditions as shown below to obtain the results set forth in Table 1.

(1) Scouring conditions Scourol No. 400 (polyoxyethylene alkylphenyl ether) Sodium pyrophosphate0.l g./1.

Liquor ratio-50:1

Treatment effected at 70 C. for min., followed by water-rinse, drying and dyeing.

(2) Dyeing conditions Dye: Fenazo Scarlet B (CI. Acid Red 66)5% OWF Assistant:H SO --2 g./l.

Liquor ratio50:l

Dyeing effected at 100 C. for 120 min., followed by water-rinse and soaping under the conditions shown below.

(3) Soaping conditions Scourol No. 400-0.5 g./l.

Sodium carbonate-0.1 g./l.

Liquor ratio-50:1

Soaping eifected at 70 C. for min., followed by water-rinse and dry.

(4) Degree of dye exhaustion Colorimetrically measured on residual solution aqueous pyridine solution as solvent (means used: Shimasus difiraction grating type Spectronic (20)) (5) Measuring method of fastness to light JISL 1044 (I959), Fade-O-meter method (corresponding to AATCC, l6A-l964). Washing fastness measuring method of fastness to washing JISL 1045 (1959), BC-2 (corresponding to AATCC, 36-19 64).

In Table 1, Sample No. 1 is the fiber in accordance with the present invention and Sample No. 2 is the control fiber.

The pyridine radial content of each sample after dyeing was measured to examine the amount of dissolving-out into the dye bath of the copolymer during dyeing. As the result, it was found that in the case of the present fiber (Sample No. 1), the copolymer had not dissolved out, whereas in the case of the control fiber (Sample No. 2), about 40% of the copolymer in the fiber had dissolved out. Further, the present fiber was markedly excellent in bath color depth and brightness as compared with the control fiber.

EXAMPLE 2 5 parts of a copolymer (1 :0.4) comprising 30 parts of stearyl acrylate and parts of 2-vinylpyridine was mixed with parts of a crystalline polypropylene powder having an intrinsic viscosity of 1.4. The mixture was treated in the same manner as in Example 1 to obtain a fiber. After scouring in the same manner as in Example 1, the fiber was treated with an aqueous sulfuric acid solution at a concentration of 2 g./l. at C. for 30 minutes, was water-rinsed and dried, and was then dyed under the following conditions:

Dyeing conditions Dye: Fenazo Scarlet B (C.I. Acid Red 66)5% OWF Assistant: H SO 0.5 g./l.

Liquor ratio50:l

Dyeing temperature and time:100 C. min.

After dyeing, the fiber was subjected to soaping in the same manner as in Example 1, whereby the fiber showed a degree of dye exhaustion of 95%, fastness to light of the 5th grade and fastness to wash of the 4-5 grade.

The dyed fiber was excellent in both brightness and color depth, and no dissolving out of the copolymer was observed at all when measured in the same manner as in Example 1.

EXAMPLE 3 5 parts of a copolymer (1;,,, =0.5 comprising 30 parts of stearyl acrylate and 70 parts of 2-methyl-5-vinylpyridine which had been obtained by polymerizing at 80 C. in toluene using benzoyl peroxide as initiator was mixed with 94.5 parts of a crystalline polypropylene powder having an intrinsic viscosity of 1.4 and 0.5 part polyoxyethylene glycol (molecular weight 4000) and as antioxidant 0.2 part of 4,4-thiobis (5-methyl-2-tert.-butylphenol). The mixture was shaped into pellets at 220 C., was subjected to melt-spinning at 260 C., and was then stretched to 5 times at C. to obtain a polypropylene fiber having such fiber mechanical property as shown in Table 2 (Sample No. 3).

TABLE 2 Elon- Sample Strength gation number Denier (g./ 1.) (percent) The above two fibers were examined in dyeability in the same manner as in Example 1 to obtain the results as shown in Table 3.

Sample No. 6 is a control fiber prepared without the addition of polyisobutylene oxide.

TABLE 3 t t TABLE Q Sample exhaustio n 3? Sample F number (P81119111?) (S number (percent) (grade) (grade) 23:11:11: 3? 2 3i 3: 3; g 2

The pyridine radical content of each fiber before and after dyeing was measured to investigate the amount of dissolving-out into the dye bath of the copolymer during The half dyeing time of Sample No. 5 was 5 minutes dyeing. As the result, it was found that in the case of the while that of Sample 6 was 10 minutes P fiber (Sample 3), dlssolvmgout of the From the above results also, it is obviously recognized copolyrner was observed, whereas in the case of the conthat the present fiber (Sample NO 5) is excellent in trol fiber (Sample No. 4) about 40% of the cop chanical property and dyeability as compared with the present in the fiber before dyeing had d1ssolved out. control fiber (Sample No. Further the present fiber Consequently the Pmsant fiber could be dyed to a was dyed to a glassy, bright red shade, whereas the cong y Ted Shade, (htireas the Control fiber. Could not be trol fiber was dyed to a color somewhat inferior in brightdyed but to a turbid red shade lacking brightness. mess to the dyed fiber of the present invention 5 t f l 0 t EXAMPLE 6 par s o a copo ymer 1 comprising par s of stearyl acrylate and 70 p its of Z-Vinylpyridine which A fiber Was Prepared under thfi Same Fondltlons as had been obtained by polymerization at 80 C. in tol- Example except. that polyprqpyleneoxlde Was used uene using azobisisobutyronitrile as initiator, and 0.5 part plaace the pqlylspbmyleneoxlqe The fiber had such of polyoxyethylene lauryl ether were mixed with 945 rsncchanical efiicienclies as a denier of 3.2, a strength of parts of a crystalline polypropylene powder. The mixture 30 i g i iolgauon 9 3 and was dyed to a was treated in the same manner as in Example 1 to obtain assyf H: t m s a Showing a agree of dye exhaus' a. fiber. This polypropylene fiber had such fiber mechani- 2 0 985% a i i hght of the 5th grade and cal properties as a denier of 3.2, a strength of 6.0 g./ d. asmess to Wash 0 t e t gra and an elongation of 30.5%. Subseguently the fiber was EXAMPLE 7 dyed under the same dyeing conditlons as in Example 1 to obtain a glassy, bright red fiber showing the degree 30 parts of stearyl acrylate, 70 parts of 2-methyl 5- of dye exhaustion of 99%, fastness to light of the 5th vinylpyridine and 1 part of azobisisobutyronitrile were grade and fastness to wash of the 5th grade, in which no charged in a polymerizer together with 300 parts of hendissolving-out into the dye bath of the copolymer during zene, and the mixture was polymerized at 75 C. for 8 dyeing was observed at all. 40 hours in a nitrogen atmosphere. After completion of the reaction, the mixture was poured into a large amount of EXAMPLE 5 petroleum ether to precipitate a copolymer. After separa- 5 parts of copolymer comprising 60 parts of 2-methyltion by filtration, the copolymer was dried under reduced 5-vinylpyridine and 40 parts of stearyl acrylate and 0.5 pressure to find that the amount of the copolymer obtained part of polyisobutylene oxide were mixed With 94.5 parts was 65 parts. As the result of nitrogen analysis, it was of crystalline polypropylene having an intrinsic viscosity found that the copolymer had a 2-methyl-5-vinylpyridine of 1.4. The mixture was further incorporated with 0.2 content of 71% by weight. part of 4,4'-thiobis (5-methyl-Z-tert.-butylphenol), was Subseque y, P yp py Was miXed h 5% by subjected to melt-spinning at 260 C., and Was then Weight of the above copolymer, and the resulting system stretched to 6 times at 120 C. to obtain a fiber. The fiber Was further miXed With each of the Phosphorus Compounds efficiencies of thus obtained fiber were shown in Table 4. as ShOWH in Table The miXtllYe Was Pelletized at The fiber was further tested in dyeability in the same man- -7 and W213 Subjected t0 melt-Spinning at and was her as in Example 1 to obtain the results as set forth in Stretched at to 5 times to Obtain a p p py Table 5. fiber- TABLE 4 The fibers thus obtained were investigated in quality of filament in the same manner as in Example 1, and were Sample Strength further subjected to dyeing tests in the same manner as number Denier (g./d.) (pa-5cm) in Example 1, except that 0.5% OWF of Solway Blue BN- 5 3 l2 6 15 30 0 150 (CI. Acid Blue 45) was used in place of 5% OW F :11:11: 12 1 of Fenazo Scarlet B, to obtain the results as shown 1n Table 6.

TABLE 6 Results oi dyeing Mechanical property Degree Elonof dye Fastness Sample Phosphorus compound (0.5 Strength gation exhaustion to light Y value Pe value number weight percent) (g./d.) (percent) (percent) (grade) (percent) (percent) n 4. s 30 93 2 11.0 54. 7 Dibutylhydrodiene phosphite 4. 7 31 95 3 10. 8 56. 4 Octadecyl phosphite 5. 1 29 03 3 10. 9 56. 8 Dodecylphosphoro-thioitc. 5.0 28 97 3 10.6 57.2 p-Nonylphenyl phosphitenn. 4. 8 30 07 34 10. 6 57. 4 3, 9-diphenoxy-2, 4, 8, 10-tetrao 4.9 32 06 3 10.9 56.0

phosphapyr0[5.5l-undecane. Totrakis (p-nonylpl1enyl-p-methylene- 5.0 31 94 3 10.0 55.8

bisphenyl diphosphite.

In Table 6, the Y and Pe values are values measured by means of Hitachi Recording Spectrophotometer, Model EPR-II (same shall apply hereinafter). From the results shown in Table 6 also, it is evident that the fibers of the present invention (Sample Nos. 8-13) are excellent fasteness to light and brightness as compared with the control fiber (Sample No. 7).

EXAMPLE 8 2-vinylpyridine was copolymerized with cetyl acrylate in the same manner as in Example 7 to obtain a copolymer containing 65% by weight of 2-vinylpyridine. Subsequently, polypropylene was mixed with 5.0% by weight of the above copolymer together with a stabilizer and was incorporated with each of the phosphorus compounds as shown in Table 7.The mixture was pelletized at 220 C. and was subjected to melt-spinning at 270 C., and was then stretched at 130 C. to times to obtain a polypropylene fiber.

The fibers thus obtained were investigated in quality of filament in the same manner as in Example 1, and were further subjected to dyeing tests in the same manner as in Example 1, except that the amount of the Fenazo Scarlet B (5% OWF) was changed to 2% OWF, to obtain the results as set forth in Table 7.

to 5 times at 130 C. to obtain a polypropylene fiber of 90 denier/ filaments. This fiber was subjected to false twisting to obtain a woolly texturized yarn having the strength, crimpability, crimp stability and strength rctention set forth in Table 9.

1 5 TAB LE 9 Strength Crnnpa- Crimp retenbility stability tion (percent) (percent) (percent In the above table, Sample Nos. 19, 20 and 21 are controls. The texturized yarn of Sample No. 19 is a fiber TAB LE 7 Results of dyeing Mechanical property Degree Elqnof dye Fastness Sample Phosphorus compound (0.5 weight Strength gation exhaustion to light Y value Pe value number percent) (g./d.) (percent) (Percent) (grade) (percent) (percent) 14 None 5. 8 23 92 3 13.0 68, 5 15 Dodecyl phosphite 5. 6 24 94 4 12.8 71. 2 16 Z-ethylhexyl phosphite 5. 4 26 3-4 13. 1 70. 7 17 p-Nonylphenyl phosphite 5. 1 25 92 4 12. 8 71, 0

As is clear from the above table, it is recognized that the present fibers are more excellent than the control fiber, like in Example 7.

EXAMPLE 9 4-vinylpyridine was copolymerized with eicosyl acrylate in the same manner as in Example 7 to obtain a copolymer containing 55% by weight of 4-vinylpyridine. Polypropylene was mixed with 6.0% by weight of the above copolymer together with a stabilizer and was further incorporated with 0.5% by weight of p-nonylphenyl phosphite. The mixture was pelletized at 220 C., was subjected to melt-spinnig at 260 C. and was stretched at C. to 5 times to obtain a fiber having a strength of 4.4 g./d. and an elongation of 25%. The fiber was subjected to dyeing tests in the same manner as in Example 1, except that 2% OWF of several dyes as shown in Table 8 were used in place at 5% OWF of Fenazo Scarlet B, to obtain the results as set forth in Table 8.

0 The crimpability referred to in the above table Was measured by applying to a filament a load of 0.5 g./d., removing the load after one minute and then effecting the following procedures: The filament was subjected to an initial load of 2 mg./d. for one minute and then to an 50 additional load of 0.1 g./d. for one minute, and the crimpability thereof was calculated according to the following equation:

crimpability: (l l /l X 100 (percent) 5 wherein Z is a length at the initial load of 2 mg./ d. and I is a length at the additional load of 0.1 g./d. The crimp TABLE 8 Phosphorus compound added fiber Control (phosphorus compound-free fiber) Degree Degree of dye Fastne-ss of dye Fastness exhaustion to light V value Pe value exhaustion to light V value Pe value Kind of dye (percent) (grade) (percent) (percent) (percent) (grade) (percent) (percent) Fenazo Scarlet B 92 4 12. 4 71. 5 90 3 12. 5 Suminol Red RS (0.1. Acid 69 4 Red 99) 92 2 13. 0 66.0 88 1 13. 4 63. 5 Solway Blue BN- 92 5-6 4. 8 58. 5 93 5 4. 8 57. 0 Xylene Fast Blue PR (0.1.

Acid Blue 129) 85 3-4 5. 3 68. 1 80 2 5. 4 66. 5

From the results of Table 8 also, it is obviously recognized that the present fibers are excellent fastness to light and brightness as compared with the controls, phosphorus compound-free fibers.

EXAMPLE 10 30 parts of stearyl acrylate, 60 parts of 2-methyl-5- vinylpyridine, 10 parts of ethyl acrylate and 1 part of stability is a value obtained by measuring 10 times re- 70 peatedly the above-mentioned crimpability and represent- 7 5 before texturization.

13 EXAMPLE 11 TAB LE 14 under the same conditions as in Example 1, using 2% OWF of Fenazo Scarlet B, whereby the dyed fiber showed a degree of dye exhaustion of 97%.

EXAMPLE 13 5 parts of a copolymer comprising 40 parts of stearyl acrylate and 60 parts of 2-vinylpyridine was mixed with 95 parts of polypropylene. The mixture was pelletized at 220 C. and was subjected to melt-spinning at 270 C.

Feed amount Dispersant Azobis- Potassium Monomer Polyprolsohutyropolyrneth- Nitrogen mixture pylene Water nitrile acrylate Yield content Sam ple number (grams) (grams) (grams) (grams) (grams) (grams) (percent) Subsequently, Sample Nos. 22 and 23 were individually incorporated with only a stabilizer, and Sample Nos. 24 and 25 were incorporated with polypropylene and a stabilizer. Each sample was adjusted to a nitrogen content of 0.4% by Weight and was pelletized at 220 C. by means of an extruder. The pellets were subjected to meltspinning at 260 C. and was stretched to 5 times at 130 C. to obtain a polypropylene fiber. The fibers thus obtained were evaluated in quality of filament and in dyeability to obtain the results as shown in Table 11, in which all of the scouring, dyeing and soaping conditions were the same as in Example 1, except that 2% OWF of Solway Blue BN-150 (CJI. Acid Blue 45) was used.

TABLE 11 Mechanical property Result of dyeing Elon- Degree gation of dye Fastness Sample Denier Strength (perexhaustion to light number (d.) (g./d.) cent) (percent) (grade) From the results shown in Table 11 also, it is obviously recognized that the fibers obtained in accordance with the present process are excellent not only in mechanical property but in dyeability.

EXAMPLE 12 100 parts by weight of a crystalline polypropylene powder having an intrinsic viscosity of 1.4 was dispersed in 500 parts by weight of hexane. To the dispersion were added 35 parts by weight of cetyl acrylate and 65 parts by weight of 2-vinylpyridine together with 1 part by weight of azobisisobutyronitrile, and the mixture was polymerized at 70 C. for 8 hours in a nitrogen atmosphere. After completion of the reaction, the reaction liquid was cooled and filtered, and the cake was washed with hexane and was then dried under reduced pressure to obtain 178 parts by weight of a white powder as product. As the result of nitrogen analysis, the nitrogen content of the product was 3.45% by weight.

For comparision, polymerization was effected in the same manner as above in the absence of the crystalline polypropylene to obtain a rubbery copolymer but no powdery polymer.

The above-mentioned product obtained according to the process of the present invention was mixed with a stabilizer and polypropylene. The mixture was adjusted to a nitrogen content of 0.35% by weight, and was then subjected to spinning and stretching in the same manner as in Example 1 to obtain a fiber. This fiber was dyed and was stretched to 5 times at 130 C. to obtain a dyeable polypropylene fiber. This fiber was scoured in the same manner as in Example 1 and was treated at 100 C. for 30 minutes at a liquor ratio of 50:1, using a treating liquid containing 3% OWF of p-tert.-octylphenol. The thus treated fiber was dyed at 100 C. for 2 hours at a liquor ratio of 50:1 in a dye bath containing 0.5% and 2.0% OWF, individually, of Fenazo Scarlet B as dye and 2 g./l. of H as assistant. The fibers after dyeing were subjected to soaping in the same manner as in Example 1 to obtain dyed fibers. The fastness to light of the dyed fibers were as shown in Table 12.

TABLE 12 Dye concen- Dye tration depo Light Sample (percent sition fastness number OWF) (percent) (grade) Example No. 28 is a control fiber which was not treated with p-tert.-octylphenol. A comparison between Sample No. 27 and Sample No. 28 shows that the treatment in accordance with the present invention is effective.

EXAMPLE 14 The procedures adopted in Example 13 were repeated, except that the fiber after scouring treatment was not treated with p-tert.-octylphenol but was dyed in the dye bath incorporated with 3% OWF of p-tert.-octylphenol. The dyed fiber showed the fastness to light set forth in Table 13.

TABLE 13 Dye concen- Degree tration of dye Fastness Sample (percent exhaustion to light number OWF) (percent) (grade) 1 EXAMPLE 16 The procedures adopted in Example 13 were repeated, except that p-nonylphenyl phosphite was used in place of the p-tert.-octylphenol. The fastness to light of the dyed fibers were as set forth in Table 14.

TABLE 14 Degree of dye Fastness Dye concentration exhaustion to light (percent OWF) (percent) (grade) The above indicates the fact that by the p-nonylphenyl phosphite treatment, the dyed fiber was greatly improved in fastness to light as compared with the control shown in Example 13.

EXAMP LE 17 EXAMPLE 18 6 parts of copolymer (1 =O.72) comprising parts of stearyl methacrylate and parts of 2-methyl-5-vinylpyridine was mixed with 94 parts of a crystalline polypropylene powder having an intrinsic viscosity of 1.4. The mixture was pelletized at 220 C., was subjected to meltspinning at 260 C. and was stretched to 6 times at C. to obtain a dyeable fiber of the present invention. The thus obtained fiber had such mechanical property as a denier of 3.0, a strength of 5.8 g./d. and an elongation of 32%. This fiber was subjected to scouring, dyeing and soaping under the same conditions as in Example 1. The dyed fiber was excellent in both color depth and brightness, showing a degree of dye exhaustion of 92%, a fastness to light of the 5th grade and a fastness to wash of the 5th grade.

EXAMPLE 19 excellent dyeability as set forth in Table 15.

TABLE 15 Degree of dye Fastness exhaustion to light Kind of dye (5% OWF) (percent) (grade) Feuazo Scarlet B 97 4-5 Solway Blue BN 92 4'5 Xylene Fast Blue-PR 94 5 What is claimed is:

1. A polypropylene fiber excellent in dyeability and texturiza-bility, characterized in that the fiber is prepared by mixing polypropylene with 130% by Weight based on the total polypropylene composition of a ternary copolymer comprising essentially 8030% by weight of a vinylpyridine, 10-60% by weight of an alkyl acrylate or methacrylate having alkyl group containing 16 to 20 carbon atoms, and up 40% by weight methyl or ethyl acrylate, and then subjecting the mixture to shaping.

2. A polypropylene fiber according to claim 1 wherein polypropylene is mixed with the copolymer and a member selected from the group consisting of a nonionic surface active agent, a polyether and mixtures thereof.

3. A polypropylene fiber according to claim 1 wherein the alkyl acrylate is stearyl acrylate.

4. A polypropylene fiber according to claim 1 wherein polypropylene is mixed with the copolymer and at least one of the phosphite esters represented by the general formulae R3X (I) wherein R R and R which may be same or different,

are individually hydrogen atom, alkyl, aryl or aralkyl group; and X is a sulfur or oxygen atom,

wherein R and R which may be same or different, are individually alkyl, aryl or aralkyl group, and

ra-o it OR9 (111 wherein R R R and R which may be same or different, are individually alkyl, aryl or aralkyl group; and R and R Which may be same or difierent, are individually hydrogen atom or alkyl, aryl or aralkyl group.

5. A polypropylene fiber according to claim '1 wherein the copolymer is prepared in the presence of a polypropylene powder.

References Cited UNITED STATES PATENTS 2,839,512 6/1958 Barnum et al. 260-86.1

3,156,743. 11/1964 Coover et al. 260897 3,162,697 12/1964 Canterino 260-878 3,375,213 3/1968 Press 260895 FOREIGN PATENTS 803,557 10/1958 Great Britain 26045.7

975,918 11/1964 Great Britain 260897 SAMUEL H. BLECH, Primary Examiner US. Cl. X.R.

8171, 173, 26023 AR, 41 B, 41 c, 45.7 P, 45.7 PS, 45.8 N, 45.85, 45.95, 80.72, 86.1 N, 895 

